ξ Ursae Majoris

Xi UMa is far to the south of the constellation. With the naked eye, it makes a sharp triangle pointing south, with phi and the two stars mu and lambda in the north; or from beta UMa, due south about 25º: binoculars.

Xi Ursae Majoris is a splendid binary, one of the most attractive in Ursa Major:
      xi UMa (Struve 1523), two yellow stars, AB: 4.3, 4.8; 187º, 1.6" with an orbit of 59.84 years.


From xi UMa and nu UMa move one binocular field north: Lalande 21185 is barely visible in the southwestern corner.

Lalande 21185 is a red dwarf, and known as one of the closest stars to the Solar System, at 8.31 light years. The 7.5 magnitude star may not be easily noticed in binoculars; Burnham has a location chart, p.1981.

Virtually next door is Groombridge 1830, two binocular fields east; a yellow subdwarf, and the third fastest known star with a proper motion of 7.058": binoculars. Groombridge 1830 is 29.9 light years away.
     Every 511 years the star shifts its position by one full degree. Brurnham has a location chart, p. 1979. Burnham points out that in 100,000 years the star will be in Lupus, and considerably fainter (9.1).

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